The legitimate case for death-row inmate Mumia Abu-Jamal’s retrial gets another airing in British helmer Marc Evans’ unfocused, oddly naive “In Prison My Whole Life.” Docu throws in the full panoply of current social-activist causes, from Abu Ghraib to Hurricane Katrina to slavery (yes, slavery) and even Paul Robeson to explain the unsurprising news that black men are given a raw deal in the U.S. Produced by Livia Giuggioli (her husband Colin Firth, star of Evans’ “Trauma,” is exec producer), and with the backing of Amnesty Intl., pic will be best appreciated by those unfamiliar with the issues involved.

Clever title comes from young activist William Francome, born the same day in 1981 that Abu-Jamal was arrested for the murder of a Philadelphia policeman. The half-English, half-American Francome becomes a tour guide of sorts through the case, making it difficult to tell whether the tone of wide-eyed surprise belongs to Evans, Francome or both.

That injustice was done seems incontrovertible. Abu-Jamal, a journalist driving a taxi to earn extra money, saw white cop Daniel Faulkner wailing on Abu-Jamal’s brother, Billy Cook. According to the prosecution, Abu-Jamal shot Faulkner in the back, then straddled the body and fired again four times. However, there’s considerable evidence that the original trial was tainted by a racist judge and police intimidation. Much of this was presented in the 1996 docu “Mumia Abu-Jamal: A Case for Reasonable Doubt?,” footage from which Evans uses here. Pic presents additional evidence that further grounds an already compelling case for a new trial.

Evans rightly attributes the death penalty judgment to Mayor Frank Rizzo’s racist political machine, presenting chilling statistics of the Philadelphia police department’s predilection for shooting black men. Abu-Jamal was a Black Panther and left-wing journalist, a bad combination at a time when the city was waging an all-out assault on the kooky but largely harmless black group Move.

None of this is new information, though there is an argument for making certain it’s not forgotten. Also not new is evidence of another man with Cook that night, and while the interview here with Cook is a first, he’s understandably reluctant to discuss the testimony he hopes to present once a retrial is finally called. Unfortunately, no one, including Abu-Jamal, will explain why they’re protecting the mystery man, now dead in what the filmmakers suggest was a police hit.

Pic presents the full range of talking heads, and while Mos Def and Snoop Dogg will appeal to younger auds, it’s elder stateswoman Angela Davis who provides the voice of reasoned intelligence, giving background and insight into the differences between the public’s mobilization over her own case and that over Abu-Jamal’s. Thanks to a Pennsylvania law passed specifically with him in mind, Abu-Jamal is unable to appear on camera, though his voice is heard in radio broadcasts.

Editing by Evans regular Mags Arnold is overly dependent on computer tricks, and use of verbal loops to reinforce lines treats the audience like idiots. Unnecessary music interrupts and nearly overwhelms Alice Walker’s interview. Digital will work best on smallscreens.